deploy: Define port_maps for Kong (OSS + Enterprise)

[mflendrich]

What this PR does / why we need it:
kong-ingress is a service exposing low ports tcp/80 and tcp/443. The implementation detail of deploy/ is that these get NAT'ed by kube-proxy to high container ports tcp/8000 and tcp/8443 of the proxy container. Without knowledge of the externally exposed low ports, Kong puts those high ports in X-Forwarded-Port request headers which end-users can consider surprising, incorrect and unnecessarily exposing the implementation details of the Kong deployment.

This PR sets KONG_PORT_MAPS to enable Kong's feature to perform a reverse address translation for the purpose of identifying the actual port a request was received on by the service.

This feature is present in Kong as of 2.1.0-beta.1, hence also an upgrade of Kong. edits per #753 (comment)

Which issue this PR fixes
closes #691

Special notes for your reviewer:

• Does not touch Kong Enterprise
• Updates kong from 2.0 to 2.1.0-beta.1 with an exception of wait-for-migrations where it updates from 1.3
• Does not touch Helm charts (to be updated in a separate PR)
• We probably want to shelve this PR until 2.1.0 gets released, and then update this PR to use 2.1.0 before merging.

[CLAassistant]

All committers have signed the CLA.

[hbagdi]

I'd recommend that we move forward with this change without waiting for 2.1 release in Kong.
Skip the version bump to beta, and limit the diff to only add the required setting. Also, we should this change for Enterprise manifests as well.
/cc @rainest

[mflendrich]

Please take a look again:

Skip the version bump to beta

done

limit the diff to only add the required setting

done (+ sorting env vars)

Also, we should this change for Enterprise manifests as well.

done

[rainest]

LGTM on the assumption that this setting is just a noop for older versions, since nothing else depends on it, which appears to be the case.